KR20010065252A - micro pick-up probe device and method for fabricating the same - Google Patents

Abstract

PURPOSE: A pickup element of a microprobe type and a fabricating method thereof are provided to accumulate horizontal/vertical drivers to integrate the drivers, and to simplify a semiconductor integrated process and an assembling process. CONSTITUTION: A system prepares a substrate. The system patterns a predetermined area of a substrate lower part to form an anchor(6), and patterns a predetermined area of a substrate upper part to form a probe(21). The system sequentially forms the first metal, a piezoelectric element and the second metal on the substrate upper part, and performs a patterning operation to form a piezoelectric actuator(11) and upper/lower electrode pads of the piezoelectric actuator(11) in a predetermined area of the substrate upper part. The system etches the substrate lower part of the area forming the probe(21) as much as predetermined depth, and then forms a cantilever(5). The system patterns predetermined areas of the substrate upper part, and forms a fixed electrode unit and a mobile electrode unit of the com-drive actuator.

Description

Micro pick-up probe device and method for fabricating the same

The present invention relates to an ultra-fine probe type pickup device applied to ultra-precision surface analysis such as atomic force microscopy (AFM), scanning probe microscopy (SPM) and the like and a method of manufacturing the same.

Recently, the generalization of the multimedia environment is largely attributed to the increase in capacity, speed, and cost per unit of information storage density.

The performance improvement of personal computers, the rapid spread of data communication such as the Internet, the appearance of VOD (video on demand), and high-definition television have large capacities that can store and process large amounts of data including moving images and audio signals in real time. There is a strong demand for information storage media.

By increasing the storage density and capacity of the existing hard disk drive (HDD), magnetic storage products have been introduced to realize high density information storage devices. However, in the case of the magnetic storage method, the recording density can be magnetized. It is known that it is quite difficult to realize more than 10 gigabytes per square inch since it is limited by its particle size.

Recently, various techniques for overcoming the limitation of recording density of a conventional HDD have been studied, and one of them is an information storage device using an atomic force microscopy (AFM) probe.

The principle of recording and reproducing the device is researched in various forms by using the existing scanning probe microscopy (SPM) method, but for controlling the position of the probe, PZT, which is a bulk piezoelectric actuator, corresponds to the Cartesian coordinate system. And a cantilever (cantilever) formed with a probe is generally used.

The bulk piezoelectric actuator serves to scan the probe in the horizontal direction of the object surface while maintaining a small gap between the probe and the surface of the object to be measured.

However, bulk actuators have a low frequency that can be driven by a relatively large volume and weight, and thus have a low speed of scanning an object surface.

In the case of a high-density information storage device, since not only the recording density but also the access speed for recording / reproducing are important parameters, the conventional probe system has a disadvantage in that high-speed data processing for the high-density recording device becomes difficult.

In addition, problems such as an increase in the volume of the system by the bulk type actuator and an increase in the system cost due to the assembly process between the actuator and the probe are also included.

SUMMARY OF THE INVENTION An object of the present invention is to provide an ultra-fine probe type pickup device and a method for manufacturing the same, which can reduce the size and weight of the device by increasing and integrating horizontal and vertical drivers.

It is another object of the present invention to simplify the assembly process and improve mass productivity by micromachining by semiconductor integrated process and micromachining technology.

1A and 1B are perspective views showing ultra-fine probe type pickup elements according to the first and second embodiments of the present invention.

2A and 2B are a perspective view, a plan view, and a cross-sectional view showing a horizontal rotationally driven ultra-fine probe type pickup element according to a first embodiment of the present invention;

3A and 3B are a perspective view, a plan view and a cross-sectional view showing a horizontal linear drive ultra-fine probe type pickup element according to a second embodiment of the present invention;

4 is a plan view showing an ultra-fine probe type pickup device according to a first embodiment of the present invention

5A to 5Q are cross-sectional views illustrating a manufacturing process along line A-A 'and B-B' of FIG. 4.

6A and 6B are a cross-sectional view and a plan view showing a high density information storage device using an ultra-fine probe type pickup device according to the present invention.

Explanation of symbols for main parts of the drawings

1: fixed part 2: movable part

3: comb electrode 4: hinge

5: cantilever 6: anchor

7: suspension spring 8: clearance

9: moving part silicon 11: piezo actuator

12: fixed part electrode pad 13: movable part electrode pad

14 piezoelectric actuator upper electrode 15 piezoelectric actuator lower electrode

21: probe 31: glass plate for support

41: horizontal rotation drive 42: horizontal linear drive

43: vertical drive 44: substrate

45: first etching mask 46: second etching mask

47: contact hole 49: piezoelectric ferroelectric

48: metal for lower electrode of piezoelectric actuator

50: metal for the upper electrode of the piezoelectric actuator

51: third etching mask 61: laser generating unit

62: position determination light detector 70: slider

71: slider suspension 80: high density information storage disk

81: data track

The ultra-fine probe type pickup element according to the present invention comprises a probe, a cantilever including a probe, a comb driving actuator for driving the cantilever in a horizontal direction, and a piezoelectric actuator for driving the cantilever in a vertical direction.

Here, the comb driving actuator has a fixed electrode portion having a plurality of grooves on the side, and a protrusion for reciprocating the inside of the groove of the fixed electrode portion corresponding to the external applied voltage, and is movable on the cantilever to move the cantilever horizontally. The fixed electrode part includes a fixing part having a plurality of grooves on one side, electrode pads formed in a predetermined area above the fixing part, and formed on a lower surface of the fixing part to provide a space of a lower surface of the fixing part. It is further configured as an anchor (anchor), the movable electrode portion is formed on the movable part attached to the cantilever and protruded on both sides of the movable part and arranged side by side in a longitudinal direction, respectively corresponding to the groove of the fixed electrode part is inserted and applied externally A plurality of electrodes moved into the groove according to the voltage, a body part connected to the movable part, and formed on the body part It is further configured to pole pad.

Here, the grooves and the electrodes may have a curved shape arranged on a concentric circle or a straight shape arranged on a straight line, and the protrusions of the movable electrode part correspond to each other in the groove of the fixed electrode part, and a part thereof is inserted therein.

The body portion and the movable portion are connected by a hinge or elastic suspension, and anchors are formed on the lower surface and the lower surface of the body portion connected to the elastic suspension to provide space of the movable portion lower surface.

In addition, a piezoelectric actuator on which the lower electrode, the piezoelectric body, and the upper electrode are stacked is formed on the movable portion, and a support glass plate is attached to the lower portion of the comb driving actuator and the piezoelectric actuator.

On the other hand, the comb drive actuator consisting of a fixed electrode portion having a plurality of grooves and a movable electrode portion having a plurality of electrodes, a piezoelectric actuator formed on the movable electrode portion, anchor, cantilever, probe ultrafine probe type pickup element of the present invention including a probe The manufacturing method includes preparing a substrate, patterning a predetermined region under the substrate to form an anchor, and patterning a predetermined region on the substrate to form a probe, and forming a first metal, a piezoelectric material, and a second metal on the substrate. Forming and patterning sequentially to form a piezoelectric actuator and upper and lower electrode pads of the piezoelectric actuator in a predetermined region on the substrate; and forming a cantilever by etching a lower portion of the substrate in the region where the probe is formed to a predetermined depth; Bonding the supporting glass plate to the lower anchor, and patterning predetermined areas on the upper substrate to drive the comb; A step of forming the fixed electrode portion and the movable electrode portion of the radiator tube.

As described above, the present invention manufactured using the semiconductor integrated process and the micromachining technique can improve the mass production, miniaturization, weight reduction, and driving speed, and can be combined with the pickup head of the information storage device to realize a high density information recording / reproducing function. have.

Other objects, features and advantages of the present invention will become apparent from the following detailed description of embodiments taken in conjunction with the accompanying drawings.

Referring to the accompanying drawings, preferred embodiments of the present invention having the features as described above are as follows.

The present invention is an ultra-fine probe type pickup device in which a micro actuator is integrated for three-dimensional position control of a probe using a semiconductor integrated process and a silicon micromachining technique.

1A and 1B are perspective views showing an ultrafine probe type pickup device according to the first and second embodiments of the present invention.

FIG. 1A is an ultrafine probe type pickup element employing a rotational drive in which the horizontal drive is a radial type 41, and FIG. 1B is an ultrafine probe type pickup element with a linear drive 42 in the horizontal direction. .

Both of these devices are manufactured in the same manner, and the vertical drive 43 is implemented by using a bending motion using a piezoelectric actuator.

As shown in Figs. 1A and 1B, the present invention provides a tip, a thin cantilever with a probe, a thick silicon comb-drive actuator for driving the cantilever horizontally, and a cantilever driven vertically. Piezoelectric actuators and the like are integrally integrated.

As such, the present invention can simplify the assembly process, can be easily applied to mass production through semiconductor integrated processes and micromachining techniques, and can significantly reduce the volume and weight of the actuator to increase search speed and searchable frequency. It becomes possible.

In addition, the present invention is assembled to a slider head used in a conventional information storage device, the pickup of a high-density information storage device to maintain a constant gap between the information storage disk and the probe element by a flying head technique The device can be implemented.

2A and 2B are a perspective view, a plan view, and a sectional view showing a horizontally driven rotationally driven ultra-fine probe type pickup device according to a first embodiment of the present invention, and FIGS. 3A and 3B are horizontal directions according to a second embodiment of the present invention. Perspective, top view and sectional view showing a linearly driven ultrafine probe type pickup element.

Comparing the first embodiment and the second embodiment of the present invention, the basic structure is the same, and in the horizontal rotation drive type structure, only the hinge 4 and the rotation driving force 41 which are flexible to rotation in the horizontal direction. And a concentric array of comb electrodes 3 centered on the narrowest part of the hinge to generate the force, and in the horizontal linear drive structure, the displacement of the movable part 2 remains linear 42. Only the shapes having the symmetrical suspension spring 7 and the comb electrodes 3 in a straight line arrangement are different.

Referring to Figures 2a, b and 3a, b will be described the three-dimensional driving of the ultra-fine probe type pickup element according to the present invention.

First, the driving in the horizontal direction applies a voltage between any one of the two fixed electrode pads 12 formed in a part of the fixed part 1 and the movable electrode pad 13 electrically connected to the movable part 2. .

Here, the fixing | fixed part 1 is being fixed to the glass plate 31 for support by an anchor, and the movable part 2 is released by the fixed interval 8 from the glass plate 31 for support.

When a voltage is applied between the fixed part electrode pad 12 and the movable part electrode pad 13, an electric field is formed between the comb electrode formed in the fixed part 1 and the movable part 2, and the movable part is moved in the horizontal direction by electrical attraction. (2) is moved toward the fixing part (1).

At this time, since the movable part 2 moves to a position where the restoring force of the hinge 4 or the suspension spring 7 is equal to the electric attraction force, the displacement of the movable part 2 can be adjusted by adjusting the input voltage.

After driving, when the voltage is removed, the movable portion 2 returns to the original equilibrium position by the restoring force of the hinge 4 or the suspension spring 7.

In the vertical driving, when a voltage is applied to both the piezoelectric actuator upper electrode pad 14 and the piezoelectric actuator lower electrode pad 15 connected to the piezoelectric actuator 11 stacked in the form of metal / piezoelectric / metal, the piezoelectric body When the electric field is induced in the piezoelectric phenomenon, a compressive stress is generated to reduce the volume of the piezoelectric body. The compressive stress causes the thin cantilever 5 to bend toward the piezoelectric body and is formed on the cantilever 5. Displacement in the vertical direction occurs in the probe 21.

The bending deflection by the piezoelectric actuator does not affect the thick movable part 2 on which the horizontal actuator is formed, and the displacement occurs only in the cantilever 5 which is thinner than the movable part 2. It can be controlled independently of each other.

In particular, the cantilever-type piezoelectric actuator applied to the vertical driver can obtain a displacement of about several micrometers even with a low applied voltage of several volts, thereby enabling low voltage driving and having a high aspect ratio made by the manufacturing method according to the present invention. Since the comb electrode can obtain a high driving force at a low voltage, the comb electrode has an advantage of significantly lowering the driving voltage compared to a probe system using a conventional piezoelectric actuator.

4 is a plan view showing an ultra-fine probe type pickup device according to a first embodiment of the present invention, Figures 5a to 5q is a cross-sectional view showing a manufacturing process along the line A-A 'and B-B' of FIG.

First, as shown in FIG. 5A, first and second etching masks 45, which function as etching masks, are formed on the front and rear surfaces of the silicon substrate 44.

Here, the first etching mask 45 may be formed by various methods such as deposition, coating, and oxidation, and may be formed of a polymer such as a silicon nitride film, a metal thin film, an oxide film, a photoresist film, and a polyimide according to a silicon etching method. Various materials such as polymers can be selected.

Subsequently, as illustrated in FIG. 5B, the pattern on which the silicon etching is to be performed is patterned on the first etching mask 45 on the back side of the silicon substrate using a semiconductor integrated process such as a photolithography process or a thin film etching process.

Then, the silicon substrate 44 is etched through the etching pattern formed as shown in FIG. 5C to form an anchor 6 having a step height of the spacer.

This can also be done by dry reactive ion etching (RIE) or by anisotropic etching of wet KOH, EDP or sumo.

Subsequently, as illustrated in FIG. 5D, the mask pattern for forming the probe is formed by using the photolithography process and the thin film etching process on the first etching mask 45 on the front surface of the substrate 44.

Thereafter, a conical shape probe 21 is formed by a dry etching method using a mask pattern formed as shown in FIG. 5E, and the front surface of the substrate 44 as shown in FIG. 5F. After removing the material of the first etching mask 45 remaining on the back and back, the second etching mask 46 is formed on the front and back of the substrate 44.

Here, the second etching mask 46 thin film may be formed by various methods such as deposition, coating, and oxidation, and may be formed of an oxide film, a nitride film, or the like having an electrical insulation function between the piezoelectric actuator and the silicon structure.

Subsequently, as illustrated in FIG. 5G, the second etching mask 46 on the back surface of the substrate 44 is used to define an etching window region where silicon anisotropic etching is to be performed by using a photolithography process and a thin film etching process.

As shown in FIG. 5H, the fixing part electrode pad and the moving part electrode pad for applying voltage to the fixing part and the moving part to the second etching mask 46 on the front surface of the substrate 44 are electrically connected to the silicon structure. Contact holes 47 are formed by a photolithography process and a thin film etching process.

Thereafter, as shown in FIG. 5I, the lower electrode metal 48, the piezoelectric ferroelectric 49, and the upper electrode metal 50 of the piezoelectric actuator are formed to form a piezoelectric actuator on the front surface of the substrate 44. After sequentially stacking, a metal / piezoelectric / metal multilayer thin film having a stacked structure as shown in FIG. 5J is patterned in the shape of the upper electrode 14 and the piezoelectric actuator 11 by a photo drawing process and a thin film etching process.

Subsequently, as shown in FIG. 5K, the shape of the lower electrode 13 is patterned by a photolithography process and a thin film etching process, and as shown in FIG. 5L, silicon deep etching is performed to implement a comb electrode shape on the front surface of the substrate 44. A third etching mask 51 material to be used is formed.

In order to realize the shape of the comb electrode, deep etching of silicon is required, and in order to deep-etch silicon, additional etching masks such as metals, oxides, and photoresists having high etch selectivity with silicon may be used. need.

As illustrated in FIG. 5M, silicon shapes such as the fixing part 1, the movable part 2, and the comb electrode 3 are patterned on the third etching mask 51 by a photo drawing process and a thin film etching process.

Subsequently, after protecting the front surface of the substrate 44 with a mechanical jig, the KOH, EDP, TMAH, etc. may be formed through an etching window on the back surface of the substrate 44 formed in the process of FIG. 5G as shown in FIG. 5N. In the silicon anisotropic etchant, after etching the silicon until the thickness of the cantilever 5 supporting the piezoelectric actuator 11 and the probe 21 remains, the second etching remaining on the back of the substrate 44 is performed. Mask 46 material is removed.

And, as shown in FIG. 5O, the anode 6 is bonded to the anchor 6 pattern for spacers formed on the back surface of the substrate 44 and the glass substrate 31 for supporting the silicon microstructure, which is prefabricated in a predetermined size. Bonding is performed by various methods such as anodic bonding, epoxy bonding, and solder bonding.

In this process, it is convenient to use the glass substrate 31 previously shaped by mechanical drilling, etc. to match the size of the fixed part 1 and the movable part 2 of a silicon microstructure.

Subsequently, as shown in FIG. 5P, the silicon deep etching is performed through the pattern of the etching mask material formed on the front surface of the substrate to fix the fixed part 1, the movable part 2, the comb electrode 3, the cantilever 5, and the like. When the microstructure is released, the third etch mask 51 remaining on the front surface of the substrate 44 as shown in FIG. 5Q is removed, and then packaged by dividing into individual device units, the microstructure is very small. The three-dimensional probe pickup element is completed.

When the ultra-small probe pickup device manufactured as described above is assembled to a slider of a disk drive, it is applied as a pickup head that can be used for a probe type high density information storage device.

6A and 6B, when the ultra-small three-dimensional probe pickup element is fixed to the slider suspension 71, the data track 51 of the rotating high density information storage disk 50 is fixed. It is a pickup head capable of recording / reproducing high density information recorded.

FIG. 6A is a sliding head technique used in a conventional magnetic disk drive (HDD) and the like, and fluidly holds the disk 50 and the probe pickup element at specific intervals, and the piezoelectric actuator 11 of the probe pickup element. By controlling the gap of the nano (region) by means of this, it is possible to record / reproduce the information of the high-density storage medium.

FIG. 6B is a conceptual diagram showing the navigation between the data tracks 51 of the disk 50. As shown in FIG. 6B, the cantilever 5 mounted with the probe 21 by the electrostatic comb electrode 3 actuator is shown in FIG. Driving linearly or rotationally in a direction parallel to the substrate surface enables ultra-tracking between fine tracks of high density information storage disks.

In the ultra-fine probe type pickup device and its manufacturing method according to the present invention has the following effects.

The present invention can be produced using a semiconductor integrated process and micromachining techniques, thereby enabling mass productivity, miniaturization, light weight, and improvement in driving speed.

In particular, the vertical and horizontal actuators integrated with the probe can increase the driving accuracy, lower the driving voltage, and greatly improve the driving frequency range.

Further, the present invention can be applied to a pickup head of an information storage device to realize a probe type high density information storage device.

Those skilled in the art will appreciate that various changes and modifications can be made without departing from the technical spirit of the present invention.

Therefore, the technical scope of the present invention should not be limited to the contents described in the embodiments, but should be defined by the claims.

Claims (13)

probe; A cantilever comprising the probe; A comb driving actuator for driving the cantilever in a horizontal direction; And, Ultra-fine probe type pickup element, characterized in that composed of a piezoelectric actuator for driving the cantilever in the vertical direction. The comb drive actuator of claim 1, wherein the comb drive actuator A fixed electrode part having a plurality of grooves on one side thereof; And a protruding portion reciprocating inside a groove of the corresponding fixed electrode portion according to an externally applied voltage, and comprising a movable electrode portion attached to the cantilever to move the cantilever in a horizontal direction. The method of claim 2, wherein the fixed electrode unit A fixing part having a plurality of grooves on one side; Electrode pads formed on a predetermined area above the fixing part; Ultra-fine probe type pickup element, characterized in that consisting of an anchor (anchor) formed on the lower surface of the fixing portion to provide space of the lower surface of the fixing portion. The ultra-fine probe type pickup device according to claim 2, wherein the grooves are curved or arranged in a straight line arranged on concentric circles. 3. The ultra-fine probe type pickup device according to claim 2, wherein the protrusions of the movable electrode portion are respectively inserted into corresponding grooves in the fixed electrode portion. The method of claim 2, wherein the movable electrode portion A movable part attached to the cantilever beam; A plurality of electrodes protruding from both sides of the movable part, arranged side by side in a longitudinal direction, corresponding to grooves of the fixed electrode part, and having a portion inserted therein and moving into the grooves according to an externally applied voltage; A body part connected to the movable part; Ultra-fine probe type pickup element, characterized in that consisting of an electrode pad formed on the body portion. 7. The ultra-fine probe type pickup device according to claim 6, wherein the electrodes have a curved shape arranged on concentric circles or a straight shape arranged on straight lines. 7. The ultra-fine probe type pickup device according to claim 6, wherein the body portion and the movable portion are connected by a hinge or an elastic suspension. The ultra-fine probe type pickup device according to claim 8, wherein the elastic suspension comprises a first elastic suspension connected to portions of both sides of the movable portion, and a second elastic suspension connecting the movable portion and the body portion. . 7. The ultra-fine probe type pickup device according to claim 6, wherein an anchor is formed on the lower surface of the body portion to provide a space of the lower surface of the movable portion. 7. The ultra-fine probe type pickup element according to claim 6, wherein the piezoelectric actuator is formed on the movable portion. In a comb drive actuator consisting of a fixed electrode portion having a plurality of grooves and a movable electrode portion having a plurality of electrodes, a piezoelectric actuator formed on the movable electrode portion, an anchor, a cantilever, a probe comprising: , A first step of preparing a substrate; A second step of forming an anchor by patterning a predetermined region under the substrate and forming a probe by patterning a predetermined region on the substrate; A third step of sequentially forming and patterning a first metal, a piezoelectric body, and a second metal on the substrate to form a piezoelectric actuator and upper / lower electrode pads of the piezoelectric actuator in a predetermined region on the substrate; A fourth step of forming a cantilever beam by etching a lower portion of the substrate in a region where the probe is formed to a predetermined depth; And, And forming a fixed electrode and a movable electrode of the comb driving actuator by patterning predetermined regions on the substrate. The method of claim 12, wherein after the fourth step, the support glass plate is bonded to the anchor under the substrate.